Kevlar/epoxy

Example 3.19 A single ply Kevlar 49/epoxy composite has the following properties. 

Fig. 7,2. Fracture toughness, R, of Kevlar 49-epoxy matrix composites (a) under varying strain rates in three-point bending and (b) at different temperatures under impact loading (O) uncoated fibers (0)41%, (Q) 63% and ( ) 100% Estapol coated fibers (A) silicone vacuum fluid (SVF) coated fibers. After Mai...

S Y Lo, H T Hahn and T T Chaio, Swelling of Kevlar 49/epoxy and S2-glass/ epoxy composites . Progress in Science and Engineering of Composites, ICCMIV, Tokyo 1982, pp 987-1000. 

Table 2.37 Property of Unidirectional Thornel 300-Kevlar 49/Epoxy Hybrid Composites (8)... 

In addition to giving a measure of the deformation within fibres, the strain-induced band shifts in Raman spectra have been used to follow the micromechanics of fibre reinforcement in model polydiacetylene/epoxy composites (13). The critical length has been measured directly (13) and the effect of resin shrinkage has been examined in detail (14,15). It has also been demonstrated that the technique can be employed to measure fibre strain optically in a high voliine fraction Kevlar 49/epoxy composite (16). In this present paper we demonstrate that Raman microscopy can also be used to measure fibre strain in carbon fibre reinforced PEEK composites (17) and to give a direct measure of residual thermal shrinkage stresses in PEEK matrix composites. 

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